Method of manufacturing a continuous magnetic foil by electrodeposition

ABSTRACT

A foil of a magnetic alloy having a uniform composition is continuously manufactured by electrodepositing the desired composition as a foil on a surface of an electrically conductive endless belt in an electrodepositing bath, peeling off the resulting deposited layer and then subjecting the layer to continuous electrolytic polishing.

United States Patent 1191 1111 3,887,440 Ichioka June 3, 1975 [54] METHOD OF MANUFACTURING A 3,239,217 2/1972 Shukovsky 204/35 R I 3, 45,857 2/1972 Fisher et al. 204/28 F0 L BY 3,647,654 3/1972 Toledo et a1 204/l29 9 3,738,922 6/1973 Toledo 204/129.9 [75] Inventor: Satoshi Ichioka, Toda, Japan FOREIGN PATENTS OR APPLICATIONS [73] Assignee Mishima Ksan Ltd-t 1,807 1/1969 Japan 204/211 Kitakyushu, Fukuoka Prefecture, Japan' Primary Examiner-John H. Mack [22] Filed: Jan. 24, 1974 Assistant Examiner-Aaron Weisstuch 1 pp No 436 376 Attorney, Agent, or Firm-Wenderoth, Lind & Ponack 57 ABSTRACT [52] Cl 332715; A foil of a magnetic alloy having a'uniform composi- [511 Int Cl C23b 7 B23 /d 5/68 tion is continuously manufactured by electrodepos- [58] Fieid 'gg 5 13 28 206 iting the desired composition as a foil on a surface of i d an electrically conductive endless belt in an electrodepositing bath, peeling off the resulting deposited layer [56] References Cited and then subjecting the layer to continuous electrolytic polishing.

4 Claims, 2 Drawing Figures METHOD OF MANUFACTURING CONTINUOUS MAGNETIC FOIL" BY ELECTRODEPOSITION BACKGROUND oF THE iNvlE T oN f The present invention relates to am'ethod of manufacturing a continuous foil of magnetic material by electrodeposition.

As is well-known. the composition of an alloy deposited by electroplating, particularly in'alloy plating, is greatly influenced-by the current'density during the electrodeposition. Therefore, in a continuous electrodeposition process, it is important to control the current density from the start to the completion of the eration in order to obtain an electrodeposited layer having a uniform alloy composition.

The above-mentioned problem is also present in the electrodeposition of'Permalloy and other magnetic alloys.'Particularly, in the manufacture of foilsof these magnetic a'lloys, themagneticcharacteristics of'the resulting magnetic foil are greatlyinfluenced by the'alloy composition deposited, so that it is most necessary that the alloy composition of the depositedl-ayer be uniform.

He'retofore, a magnetic alloy has been electrodeposited on a continuously moving base conductor by'electrodeposition and then recovered as it -is' or peeled off the conductor to obtain a continuous thin film such as a foil or tape-like magnetic "alloy.'However, even if it'is very difficult to prevent'the occurrence of such an abnormal current.

That is, in the portion of the electrolyte where the base conductor enters the electrolyte, even if no power source is connected to the anode, a cell is partially constituted by the anode, the electrodepositing bath and,

the cathode, and the electrolyte surrounding the base conductor causes changes in the electrodepositing bath, whereby an abnormal current due to electrochemical reaction flows rapidly. This abnormal current is added to the normal electrodepositing current during:

electrodeposition. Consequently, the abnormal current acts for a certain length of time during initial electrodeposition, for example. when Permalloy is deposited to a thickness of about 2000 A by a general electrodeposition. Therefore, there is the disadvantage that the re-.-'

sulting alloy composition changes in an undesirable way due to this abnormal current.

SUMMARY OF THE INVENTION An object of the present invention is to overcome the" above described disadvantages and to improve the magnetic characteristics of magnetic foils by homogenizing the alloy composition in the direction of the thickness of a film or foil formed during continuous electrodeposition.

The inventor has recognized that in the continuous production of foils of magnetic material by electrodeposition, the portion having a non-uniform alloy composition as described above occurs mainly in the initially deposited portion of the layer, and he has made various investigations with respect to the manufacture of foils of magnetic material having a uniform alloy composition, and as a result has found that the above described-problems can be solved by providing an electrolytic polishing step subsequent to the electrodeposition stage'so as to remove the initially deposited portion ofthedayrzwi'thout technical difficulty.

Accordingly, the present invention is a method of manufacturing a continuous foil of magnetic material by electrodeposition, which comprises electrodepositing a magnetic alloy layer on a surface of an endless base conductor belt in an electrodepositing bath composed of a plurality of electrodeposition chambers. peeling off the resulting deposited layer after it has reached the desired thickness, and then subjecting the deposited layer to a continuous electrolytic polishing so as to remove the initially deposited portion thereof to leave a foil of magnetic material having a uniform composition. According to the present invention. a foil of magnetic material having a uniform alloy composition can be continuously manufactured and it is possible to improve the magnetic characteristics of the resulting foil considerably.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagrammatic view of an apparatus for practising the method of the present invention; and

FIG. 2 is a graph showing the magnetic characteristic of a foil made by the method of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT :Referring to FIG. 1, an electrodepositing bath apparatusv 2 comprises a plurality of electrodeposition chambers l, 1' An endless base conductor belt 3 is continuously passed through the chambers l, 1 of the electrodepositing bath apparatus 2. The current density in each of the electrodeposition chambers 1, 1' of the electrodepositing bath apparatus 2 is controlled by a current controlling device 4, whereby a magnetic alloy of the desired composition is electrodeposited on the surface of the base conductor in each electrodeposition chamber. The endless belt 3 is the base conductor for electrodeposition and can be any electrically conductive material such as stainless steel or the like. In order that the resulting deposited layer can be easily peeled off the endless belt, it is desirable that the composition of the electrodepositing bath be appropriately selected and the surface of the endless belt 3 is polished in an appropriate conventional manner to, for example, a surface roughness of less than 1 After the electrodeposition, the deposited layer is peeled off the base conductor by a peeling roller 5 or the like to obtain the layer 6. However, in this layer the alloy composition is non-uniform in the direction of the thickness thereof, as described above, and such nonuniform portion is mainly the initially deposited portion on the bottom surface of the layer 6 as seen in FIG. 1. Therefore, after removing only the initially deposited portion by means of an electrolytic polishing bath having a composition depending on the alloy composition, the composition of the remaining portion of the layer 6 is substantially homogeneous throughout.

As shown in FIG. 1, the deposited layer 6 is introduced into an electrolytic polishing bath 7 by being guided under a roller 8 so as to electrolytically polish only the initially deposited portion of the layer. After the initially deposited portion is removed in the electrolytic polishing bath 9 by a cathode 10 which is at a restricted voltage, the resulting foil 11 is wound up on a winding roller in a roll 12.

The following example is given in illustration of this invention and is not intended as limitation thereof.

EXAMPLE Composition of electrodepositing bath based on 1 liter of water nickel sulfaminate 200 cell. iron sult'aminate 100 cell. potassium citrate 100 cell. sodium hydrogen sulfite 3 g/l.

saccharin l g/] aqueous 28% ammonia regulating of pH Conditions of electrodeposition pH above 9.0

temperature above 65C current density l-5 A/dm cathodic material stainless steel anodic material nickel Composition of electrolytic polishing bath phosphoric acid 7 parts by volume sulfuric acid 3 parts by volume water 0.8 part by volume Condition of electrolytic polishing temperature 80 current density 20 A/dm polishing time 10 sec.

(the measuring condition was the same as described above). a

From the B-H curve as shown in FIG. 2, it is clear that the magnetic properties of the magnetic foil obtained by the method of the present invention (curve 2) are greatly improved as compared with those of the foil produced under the same conditions, but not subjected to the electrolytic polishing treatment (curve 1 As described above. by the method of manufacturing a continuous foil of magnetic material according to the present invention, a magnetic foil having a very uniform alloy composition can be obtained without the use of a particular base for electrodeposition and a specific electrodeposition method. so that the present invention has considerable industrial merit.

What isclaimed is:

l. A method of manufacturing a continuous foil of magnetic material by electrodeposition. which comprises electrodepositing a desired magnetic alloy layer on a surface of an endless base conductor belt for electrodeposition in an electrodepositing bath composed of -a plurality of electrodeposition chambers. peeling off the resulting deposited layer in a desired thickness, and then subjecting the deposited layer to a continuous electrolytic polishing so as to remove an initially deposited portion, whereby there remains a magnetic foil of uniform composition.

2. The method as claimed in claim 1 further comprising controlling the current density in each of said electrodeposition chambers by a current controlling device.

3. The method as claimed in claim 1 wherein said belt is stainless .steel.

4. The method as claimed in claim 1 wherein the surface of said belt has a roughness less than lu. 

1. A method of manufacturing a continuous foil of magnetic material by electrodeposition, which comprises electrodepositing a desired magnetic alloy layer on a surface of an endless base conductor belt for electrodeposition in an electrodepositing bath composed of a plurality of electrodeposition chambers, peeling off the resulting deposited layer in a desired thickness, and then subjecting the deposited layer to a continuous electrolytic polishing so as to remove an initially deposited portion, whereby there remains a magnetic foil of uniform composition.
 1. A METHOD OF MANUFACTURING A CONTINUOUS FOIL OF MAGNETIC MATERIAL BY ELECTRODEPOSITION, WHICH COMPRISES ELECTRODEPOSITING A DESIRED MAGNETIC ALLOY LAYER ON A SURFACE OF AN ENDLESS BASE CONDUCTOR BELT FOR ELECTRODEPOSITION IN AN ELECTRODEPOSITING BATH COMPOSED OF A PLURALITY OF ELECTRODEPOSITION CHAMBERS, PEELING OFF THE RESULTING DEPOSITED LAYER IN A DESIRED THICKNESS, AND THEN SUBJECTING THE DEPOSITED LAYER TO A CONTINUOUS ELECTROLYTIC POLISHING SO AS TO REMOVE AN INITIALLY DEPOSLITED PORTION, WHEREBY THERE REMAINS A MAGNETIC FOIL OF UNIFORM COMPOSITION.
 2. The method as claimed in claim 1 further comprising controlling the current density in each of said electrodeposition chambers by a current controlling device.
 3. The method as claimed in claim 1 wherein said belt is stainless steel. 